1. Field of the Invention
The present invention is generally related to steering actuators and, more particularly, to a steering actuator which uses hydraulic pressure to move a motive member along a reciprocal path and an actuator member which is movable in a direction generally perpendicular to the reciprocal path.
2. Description of the Related Art
Those skilled in the art of steering systems for outboard motors are familiar with many different types of actuators that are used to convert hydraulic pressure to rotation of an outboard motor about its steering axis.
U.S. Pat. No. 4,773,882, which issued to Rump on Sep. 27, 1988, describes a hydraulic steering assembly for outboard engines. The assembly is secured to a tiller arm of a variety of outboard propulsion units in order to rotate a propulsion unit about its steering axis. The assembly comprises a hydraulic cylinder having a hydraulically actuated rod member extending therefrom and being rotatably secured to the tiller arm of an outboard propulsion unit about an axis of rotation parallel to the steering axis.
U.S. Pat. No. 5,542,864, which issued to Peebles on Aug. 6, 1996, describes a steering cylinder for an outboard engine. The hydraulic cylinder has an elongate interior chamber, a piston movable in the chamber, and a first fluid passage generally parallel to the chamber. In the improvement, the cylinder includes a second fluid passage generally parallel to the chamber and both passages terminate at faces at either end of the cylinder housing.
U.S. Pat. No. 5,092,801, which issued to McBeth on Mar. 3, 1992, describes a hydraulic steering assembly for outboard marine engines. The assembly is connected to the tiller arm of an outboard marine engine and includes a piston rod supported for arcuate movement about the tilt axis while remaining parallel thereto. A hydraulic cylinder travels along the piston rod. An arm extends from the cylinder to a first pivotal member establishing a first pivotal connection about an axis parallel to the tilt axis. A rigid link extends between the first pivotal member and a second pivotal member. The second pivotal member is also connected to the tiller arm and establishes a second pivotal connection about an axis perpendicular to the tilt axis.
U.S. Pat. No. 5,213,527, which issued to Fetchko on Mar. 25, 1993, describes a marine power steering actuator system. An actuator assembly is provided for a powered steering ram of a marine inboard/outboard drive of the type where the ram is connected to a tiller arm and has a spool valve mounted on the ram. The spool valve has a fastening tube which opens the spool valve when displaced in either direction to supply hydraulic fluid to the ram to move the tiller arm in the direction the fastening tube is displaced.
U.S. Pat. No. 5,241,894, which issued to Hundertmark on Sep. 7, 1993, discloses a marine power steering system. The system is for operation of a power steering assembly and includes a pressure accumulator to provide pressurized hydraulic fluid and valving that permits the transfer of hydraulic fluid within the cylinder to provide efficient use of hydraulic fluid.
U.S. Pat. No. 5,427,045, which issued to Fetchko on Jun. 27, 1995, describes a steering cylinder with integral servo and valve. The steering actuator is operatively connected to the tiller of the craft. A hydraulic servo actuator is mounted on the steering actuator. The servo actuator is permitted limited axial displacement relative to the steering actuator. The servo actuator is operatively connected to the steering actuator. A servo valve is mounted on the actuator assembly and has ports for receiving pressurized hydraulic fluid.
U.S. Pat. No. 5,471,907, which issued to Kobelt on Dec. 5, 1995, describes a marine steering apparatus. A fluid power apparatus is connected to a pressurized fluid supply and a conventional helm pump controlled by the helm of a vessel to shift the rudder. The apparatus comprises an actuator cylinder connected to the rudder, and a servo cylinder and a main valve connected to the helm pump to pass fluid therebetween and between the actuator cylinder. The actuator cylinder and servo cylinder have respective bodies and piston rods, and portions of the servo cylinder and actuator cylinder are connected together for concurrent simultaneous movement along respective longitudinal axes.
U.S. Pat. No. 5,658,177, which issued to Wagner on Aug. 19, 1997, describes a mounting arrangement for an engine steering cylinder. The mounting bracket is used to couple a hydraulic steering cylinder to one of first and second brands of outboard engines. Such bracket has first and second groups of holes, the holes comprising each group positionally corresponding to a bracket attachment hole in the first or second brand of engine.
U.S. Pat. No. 5,997,370, which issued to Fetchko et al. on Dec. 7, 1999, describes an outboard hydraulic steering assembly with reduced support bracket rotation. A hydraulic steering assembly applies a force to a tiller arm of a marine outboard propulsion unit and rotates the propulsion unit about a steering axis between a center position and hard over positions to each side of the center position. The propulsion unit is supported for arcuate movement about a tilt axis which is generally perpendicular to the steering axis. The steering assembly includes a hydraulic steering cylinder with an elongated piston rod reciprocatingly mounted within the cylinder for movement along a piston rod axis. A pair of support arms are pivotable about the tilt axis and are connected to the piston rod, allowing arcuate movement of the rod about the tilt axis, while maintaining the rod axis parallel to the tilt axis.
U.S. Pat. No. 6,276,977, which issued to Treinen et al. on Aug. 21, 2001, discloses an integrated hydraulic steering actuator. The actuator is provided for an outboard motor system in which the cylinder and piston of the actuator are disposed within a cylindrical cavity inside a cylindrical portion of a swivel bracket. The piston within the cylinder of the actuator is attached to at least one rod that extends through clearance holes of a clamp bracket and is connectable to a steering arm of an outboard motor. The one or more rods attached to the piston are aligned coaxially with an axis of rotation about which the swivel bracket rotates when the outboard motor is trimmed. As a result, no relative movement occurs between the outboard motor, the rod attached to the piston of the actuator, and the swivel bracket during rotation of the outboard motor about the axis of rotation.
U.S. Pat. No. 6,402,577, which issued to Treinen et al. on Jun. 11, 2002, discloses an integrated hydraulic steering system for a marine propulsion unit. The system is provided in which a steering actuator is an integral portion of the support structure of a marine propulsion system. A steering arm is contained completely within the support structure of the marine propulsion system and disposed about its steering axis. An extension of the steering arm extends into a sliding joint which has a linear component and a rotational component which allow the extension of the steering arm to move relative to a movable second portion of the steering actuator. The movable second portion of the steering actuator moves linearly within a cylinder cavity formed in a first portion of the steering actuator.
U.S. Pat. No. 6,761,599, which issued to Ferguson on Jul. 13, 2004, describes a marine steering system having a swivel bracket forming hydraulic cylinder. The apparatus for a marine craft has a first bracket connectable to the stern of the marine craft. There is a second bracket connectable to the propulsion unit of the marine craft. The second bracket is rotatably connected to the first bracket for relative rotation about an axis of rotation. The propulsion unit can be rotated about the axis of rotation relative to the stern of the craft. The second bracket has a cylindrical bore extending therethrough. A piston is reciprocatingly received within the bore. The piston slidingly engages the bore and has a piston rod connected thereto. The piston rod is operatively connected to the propulsion unit.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.